The present invention relates to a system and method for updating data in a geographical database navigation data systems, and more particularly, the present invention relates to a system and method for providing incremental updates of geographical data for databases used in computer-based navigation systems.
Computer-based navigation systems for use on land have become available in a variety of forms and for a variety of applications. One exemplary type of navigation system uses (1) a detailed data set (or map) of a geographical area, (2) a navigation application program, and, optionally, (3) a positioning system. The detailed geographical data set portion of the navigation system is in the form of one or more detailed, organized data files or databases. The detailed geographical data set may include information about the positions of roads and intersections in or related to a specific geographical area, and may also include information about one-way streets, traffic signals, stop signs, turn restrictions, street addresses, alternative routes, hotels, restaurants, museums, stadiums, offices, automobile dealerships, auto repair shops, etc.
The positioning system may employ any of several well-known technologies to determine or approximate one""s physical geographic location. For example, the positioning system may employ a GPS-type system (global positioning system), a xe2x80x9cdead reckoningxe2x80x9d-type system, or combinations of these, or other systems, all of which are well-known in the art.
The navigation application program portion of the navigation system is a software program that uses the detailed geographical data set and the positioning system (when employed). The navigation application program may provide the user with a graphical display (e.g. a xe2x80x9cmapxe2x80x9d) of his specific location in the geographical area. In addition, the navigation application program may also provide the user with specific directions to locations in the geographical area from wherever he is located.
Some navigation systems combine the navigation application program, geographical data set, and optionally, the positioning system into a single unit. Such single unit systems can be installed in vehicles or carried by persons. Alternatively, navigation application programs and geographical datasets may be provided as software products that are sold or licensed to users to load in their own personal computers. Personal computer-based systems may be stand alone systems or may utilize a communication link to a central or regional system. Alternatively, the navigation system may be centrally or regionally located and accessible to multiple users on an xe2x80x9cas neededxe2x80x9d basis, or alternatively, on line via a communications link. Navigation systems are also used by operators of vehicle fleets such as trucking companies, package delivery services, and so on. Navigation systems may also be used by entities concerned with traffic control and traffic monitoring. In-vehicle navigation systems may use a wireless communication connection. Also, users may access a central navigation system over an on-line service such as the Internet, or over private dial-up services, such as Compuserve, Prodigy, and America Online.
Computer-based navigation systems hold the promise of providing high levels of navigation assistance to users. Navigation systems can provide detailed instructions for travelling to a desired destination, thereby reducing travel time and expenses. Navigation systems also can provide enhanced navigation features such as helping travellers avoid construction delays and finding the quickest route to a desired destination.
One potential obstacle to providing enhanced features with a navigation system is the need to update the geographical information used by the navigation system. Just like conventional printed maps, geographical information used by computer-based navigation systems becomes out-of-date, (i.e. geographical information is xe2x80x9cperishablexe2x80x9d). For example, new roads are built, businesses change locations, road construction closes roads, detours are established, museum and restaurant hours change, etc.
In one known system, updated versions of geographical information are released on a periodic basis. In this known system, a user who wants to update his geographical database is required to replace his entire previous geographical database with a new version. This can be burdensome because of the large amount of data involved, much of which is identical to the data in the user""s previous version of the geographical database. Furthermore, in such a system, new releases of geographical data may be made on a fixed periodic schedule (e.g. every several months such as every three months). Thus, a user""s geographical database has the potential for being out-of-date thereby decreasing its usefulness.
Accordingly, a system and method are desired that would provide for improved updating of geographical databases used in navigation systems. Further, there is needed a system and method for updating a geographical database in an efficient manner and on a frequent basis.
To achieve the foregoing and other objectives and in accordance with the purposes of the present invention, there is provided an improved method and system that provides incremental updates for a geographical data set for use in navigation systems. The system and method include organizing updates of a geographical data set into a series of transactions. Each of the transactions includes a transaction identifier that uniquely identifies the transaction, and n steps to be applied to the geographical data set to complete the transaction. All the steps of the transaction are required to be successfully applied in order for the transaction to be completed, otherwise, the entire transaction is not applied.